Hey!
Trying to figure out a rather “non-destructive” way to automatically route the input to output of pisound when jack.service is starting. Tried ExecPost …but this is not working (…which makes sense). I read a lot about meta services etc. but this is all kind of confusing - what is the correct way of launching my
Jack_connect.sh
#!/bin/bash
/usr/local/bin/jack_connect system:capture_2 system:playback_2 ; /usr/local/bin/jack_connect system:capture_1 system:playback_1
script (or the commands inside of it)?
Any help is much appreciated!
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Hi, you could create your own .service file that would run after jack.service gets started (using After=jack.service). Make sure that you have EnvironmentFile=/etc/environment in your .service. (check pisound-btn.service as an example). This is so that the service imports the environment variables necessary to access the shared Jack backend.
Make sure that /usr/local/bin/jack_connect is the right path, the ‘local’ is usually used for software compiled locally, but jack is installed as a .deb package on Patchbox OS image, so normally the path should be /usr/bin/jack_connect. (however, I don’t have access to RPi atm, so can’t double check)
It may be useful in your script to call jack_wait first, this command should wait until Jack backend is fully started.
Also make sure that ‘chmod +x’ has been done on your script. 
2 Likes
Hey @Giedrius!
Thanks for the really useful tipps!
It works!
jackc.service
[Unit]
Description=Jack Connect daemon autostart
After=jack.service
[Service]
EnvironmentFile=/etc/environment
User=jack
Group=jack
ExecStart=/home/patch/Jack_connect.sh
CPUSchedulingPriority=95
CPUSchedulingPolicy=rr
MemoryLimit=512M
MemorySoftLimit=512M
LimitRTPRIO=infinity
LimitRTTIME=infinity
LimitMEMLOCK=infinity
[Install]
WantedBy=jack.service
I had to add those Scheduling / RT additions to avoid Buffering Allocation errors - but this seems to do the job.
The Jack_connect.sh looks like this:
#!/bin/bash
/usr/bin/jack_wait -w ; /usr/bin/jack_connect system:capture_2 system:playback_2 ; /usr/bin/jack_connect system:capture_1 system:playback_1
And then I edited the /etc/systemd/system/multi-user.target.wants/jack.service - I added Wants=jackc.service
jack.service
[Unit]
Description=JACK Server
After=sound.target
Wants=jackc.service
[Service]
LimitRTPRIO=infinity
LimitMEMLOCK=infinity
Environment=JACK_NO_AUDIO_RESERVATION=1
Environment=JACK_PROMISCUOUS_SERVER=jack
ExecStart=/etc/jackdrc
User=jack
Group=jack
[Install]
WantedBy=multi-user.target
Edit: Found the solution and edited post accordingly - maybe I didn’t do it all correctly - I am open for suggestion how to improve this
1 Like
I think you don’t need to edit this by hand, just create your .service in /usr/lib/systemd/system, then run: (assuming you named your file jackc.service)
sudo systemctl daemon-reload # This picks up the changes in .service files
sudo systemctl start jackc.service # This runs the service immediately
sudo systemctl enable jackc.service # This enables running on boot
without this …it didn’t work with sudo systemctl restart jack (or rather stop and then start in my case) but only at startup
I tried this but it didn’t do the job - iirc I tried the PartOf=jack.service in the jackc.service before adding Wants=jackc.service. Anyways …this works - won’t touch this anymore if that is the only thing that comes to your mind when looking at this solution.